Thermal development apparatuses performing the thermal development process of forming a latent image in a sheet film of a photothermographic material and heating the film to develop the latent image to visualize the image are commonly known, in which the sheet film stored in a container is picked-up to convey and supply the sheet film downstream. Conventionally, a vacuum pad system has been adopted, in which sheet film is lifted up, while performing vacuum adsorption of the sheet film by a pad. However, such a vacuum pad system in which the time required for pickup becomes longer, cannot be chosen from the point of view of requirement for rapid access of the thermal development process.
To minimize the time required for pickup for the reason described above is preferred a feed roller system, in which sheet film is fed by bringing a roller into contact with the uppermost sheet film, as described, for example, in U.S. Pat. No. 5,660,384.
However, when plural sheets of film stacked in a container are each fed by a feed roller, the sheet film to be fed is moved in the direction parallel to the film, while being in contact with the lower film and being rubbed, producing problems that abrasion easily occurs.
It is also known that in photothermographic materials, matting agents are usually used or the surface roughness thereof is adjusted, as described in published Japanese translation of PCT International Patent Application Publication No. 5660384, U.S. Patent Application Publication No. 2005/0250057 and JP-A No. 2000-112062 (hereinafter, the term, JP-A refers to Japanese Patent Application Publication).